Burnishing apparatus



J. T. YOVANOVICH BURNISHING APPARATUS April 23, 1957 2 Sheets-Sheet 1 Filed Sept. 27, 1955 INVENT OR. JOSEPH T. YOVANOVICH FIG.

ATTORNEYS April 23, 1957 I 1 J. T. YOVANOVICH 2,789,484

I BURNISI-IING APPARATUS Filed Sept. 27, 1955 2 Sheets-Sheet 2 I0 INVENTOR. F I G. 2

JOg EPH T YOVANOVICH ATTORNEYS United States Patent BURNISHING APPARATUS Joseph T. Yovanovich, Rosemont, Pa., assignor to Paper Research & Development Corporation, Philadelphia, Pa., a corporation of Pennsylvania Application September 27, 1955, Serial No. 536,930

7 Claims. (Cl. 93-83) This invention relates to tube burnishing apparatus and, more particularly, to apparatus for surface finishing and sizing spiral wound paper tubes, but is not limited to tubes of this particular type.

It frequently occurs in the manufacture of tubes that the outside diameter of the tube must be provided to extremely close tolerances. When the manufacturing process does not permit the control of tube diameter to within these tolerances, it is necessary, after the tube has been manufactured, to perform what is commonly referred to as a sizing operation.

Furthermore, the manufacture of many tubes and particularly the manufacture of spiral wrapped tubes is attended with ditficulty in controlling the relative positions of adjacent edges of successive convolutions of the spiral wound material from which the tube is formed. Particularly when the outer wrapping of the tube is not wound with edges of adjacent convolutions in precise engagement with each other, the outer surface of the tube is marred by a spirally extending groove or ridge depending upon whether the adjacent edges of the successive convolutions were spaced apart or were in overlapping relation.

In order to insure an accurate outside diameter of a finished tube and in order to substantially eliminate from the surface of a tube spiral irregularities such as those noted,

it is common practice to pass the tube through a ring die which is of slightly smaller inside diameter than the outside diameter of the tube passing thereto. Generally, the die is rotated and sometimes the tube is also rotated as the tube is passed through the die. These relative motions of the engaging die and tube surfaces serve to burnish the surface of the tube levelling irregularities therein and producing accurate external tube diameters.

Heretofore, in such operations, a substantial amount of power was consumed and a substantial amount of heat was generated due to the friction occuring between the surfaces of the die and the tube being burnished. Even attempts to provide surface lubrication of the tube being burnished have been only partially effective in providing any substantial reduction in heat loss and power consumption.

It is the object of this invention to provide apparatus for burnishing, i. e., for finishing and/ or sizing, the exterior surface of a tube by means of which the burnishing may be accomplished with a heat loss and power consumption substantially less than that involved in burnishing apparatus heretofore employed.

It is a further object of the invention to provide a rotating burnishing ring or die which is mounted to vibrate at high frequencies, i. e., of the order of 30,000 to 80,000 cycles per second, during the burnishing operation.

These and other objects of the invention relating particularly to the construction of apparatus embodying the invention will become evident from the following description when read in conjunction with the accompanying drawings in which:

Figure 1 is an elevation of apparatus embodying the invention; and

Figure 2 is a fragmentary section through the apparatus taken on the trace 22 shown in Figure 1.

In the figures there is shown a base plate 2 supporting an upstanding mounting plate 4. The plate 4 is provided with a bore 6 over which a plate 8 is rotatably mounted in rollers 10 which are supported from the plate 6 by means of bolts 12. The bolts 12 are provided with shoulders bearing against the plate 6 to provide clearance between the bolt heads and the plate in order that the rollers 10 may rotate freely. The rollers 10 and the plate 8 are provided with mating V-cut surfaces, as indicated at'14, in order to retain the plate 8 in proper position in the rollers 10.

The central portion of the plate 8 is provided with a bore 16 and the outer edge portion of a rubber ring disc 18 is attached to the disc 8 by means of bolts 20 passing through a clamping ring 21 and extends over a portion of the bore 16 in the plate 8. The rubber ring disc 18 is provided with a central bore 20 and mounts a burnishing ring die 22 havingan inner surface 24 adapted to bear upon a tube being burnished positioned as indicated by the construction lines 26. The burnishing ring 22 is afiixed to the rubber ring 18 by means of bolts 28 and a clamping ring 29.

Adjacent to the outer peripheral surface of the plate 8 there is mounted an annular member 30 which is affixed to the plate 8 by means of bolts 32. The outermost portion of the annular member 30 is provided with gear teeth 34 over which there is passed a chain belt 36 which also passes over and is driven by a sprocket 38 mounted on the shaft of and driven by a motor 40 supported by means of a suitable bracket 42 attached to the plate 4. The motor wiring and starter mechanism is entirely conventional and thus need not be described herein.

A vibration generator 44 is mounted by suitable mounting means including a spacer block 46 to the circular plate 8. The vibration output of the vibration generator 44 is delivered from a vibrating element 45 through connecting means 45' to the sizing ring 24. Diametrically across the opening in the sizing ring 24 from the vibration generator 44 is mounted a counterweight 50. This counterweight is, of course, provided to balance the weight of the vibrator when the entire assembly is rotated by the motor 40.

The vibration generator includes the vibratory element 45 which is driven by magnetostrictive driving means including a stack 47 of thin laminae of nickel and a coil 49 of wire wound thereon. This type of vibration generator is well known and is more fully described in the patent to Calosi 2,632,858 and in the patent to Mason 2,514,080.

The coil 49 is connected through conductors 52 to annular contact strips 54 which are mounted in spaced relation on an insulating strip 56 affixed to the member 30. A pair of contact arms 58 are supported by insulating mounting means 59 and supported from the plate 40. Conductors 61 connect the contact arms 58 to a suitable source 63 of high frequency current which is energized through conductors 65 connected to a conventional power source. The high frequency source 63 may be of any conventional type and thus need not be described in detail herein. It is important to note, however, that the vibration generator is positioned to vibrate the sizing ring on sub stantially a radial plane while the ring is rotating and that a suitable source of energizing current is connected to the vibrator through contact arms 58, the annular rings 54 and the conductors 52. While a magnetostriction type of vibrator has been described, it will be evident that-magnetic,- rotating and other well known types of vibrators may be employed.

In operation of the device, the tube is positioned inside the opening 24 in the sizing ring 22 in the position as is indicated by the construction lines 26. The vibrator is energized to cause the sizing ring to vibrate as'itisfree to do. by reason of its mounting in the rubbenmounting ring 18. The motor 40 is provided with a source of power and connected thereto in conventional manner. Operation of the motor 40 will drive the chain 36 andthe rotatable plate 8 which is mounted in the rollers 19. Upon rotation of the plate 8 and operation of the vibrator, the sizing disc 22 will rotate around the tube extending therethrough-and will vibrate while so rotating. The tube being drawn or pushed through the sizing ringby conventional means may bepassed through in a linear manner or may be rotated as it is passed through the die. In any event, as the tube passes through the die, the die not only rubs over the surface of the tube, but by virtue of the vibration, acts as a peening tool. It will be evident that if the sizing ring is rotating at a substantial rate Off. speed and the vibrator is vibrating at a reasonably high frequency, the peening will be accomplished by a multiplicity of small blows distributed over the entire surface of the tube and thus will not cause any local depressions, but will rather facilitate the sizing operation and improve the sized tube surface.

By way of example, it may be stated that in one apparatus a sizing ring of approximately three inch diameter was mounted on a rubber ring plate A; of an inch thick and rotated at the rate of approximately 600 R. I. .M. being vibrated at approximately 60,000 cycles per second. The tube was forced through the ring at a linear velocity or" approximately 80 feet per minute. In this operation the force required to pass the tube through the sizing ring when it was being vibrated was less than 45% of the force required to pass the tube through the sizing ring when the sizing ring was not being vibrated and the resulting tube surface was improved due to the absence of generation ofheat thereon by friction between the relatively moving surface, particularly where the tube diameter was increased such as, for example, by local projections thereon. It will be evident that the possible range of frequencies and amplitudes of vibration are quite broad and that optimum conditions offrequency, amplitude and rotational speeds will depend upon the material and condition of the tube surface and the degree of} sizing or burnishing involved. It is desirable, however, to. employ vibration, rates in the ultrasonic range. Low frequency vibrations are of relatively little aid and, in some instances, give rise to a loss of power due to vibrationof the entire apparatus which is greater than the power saving resulting from the peening efiectdue to the vibrations.

'What is claimed is:

1'. Tube burnishing apparatus comprising a burnishing die having a bore for the reception of a tube to be burnished, means for rotating said die around the longitudinal axis of said bore, and means for vibrating said die during rotation thereof for rapid oscillation while in engagement with a tube extending through said bore therein.

2. Tube burnishing apparatus comprising a burnishing die having a bore for the reception of a tube to be burnished, elastic means supporting said die, means for rotating said die around the longitudinal axis of said bore, and means for vibratingsaid die during rotation thereof for rapid oscillation while in engagement with a tube extending through said bore therein.

3. Tube burnishing apparatus comprising a burnishing die having a circular bore for the reception of a tube to be burnished, elastic means supporting said die, rotatable means mounting said elastic means, means for rotating said rotatable means around a center of rotation coincident with the center of said bore in said die, means for vibrating said die for rapid oscillation while in engagement with a tube extending through said bore therein.

4. Tube burnishing apparatus comprising a burnishing die having a circular bore for the reception of a tube to be burnished, elastic means supporting said die, rotatable means mounting said elastic means, means for rotating said rotatable means around a center of rotation coincident with the center of said bore in said die, means mounted on said rotatable means for vibrating said die for rapid oscillation while in engagement with a tube extending through said bore therein.

5. Tube burnishing apparatus comprising a burnishing die having a circular bore for the reception of a tube to be burnished, elastic means supporting said die, T0- tatable means mounting said elastic means, means for rotating said rotatable means around a center of rotation coincident with the center of said bore in said die, means mounted on said rotatable means for vibrating said die for rapid oscillation on a plane extending radially of a tube extending through said bore therein.

6. Tube burnishing apparatus comprising a burnishing die having a bore for the reception of a tube to be burnished, and means for vibrating said die for rapid oscillation on an axis extending transversely of a tube extending through said bore therein and means for providing relative rotation between said die'and said tube extending therethrough.

7. Tube burnishing apparatus comprising a burnishing die having a bore for the receptionof a tube to be burnished, elastic means mounting said die for coordinate movement on a plane extending radially of the bore therein, and means for vibrating said die for rapid oscillation on said plane.

References Cited in the file of this patent UNITED STATES PATENTS 938,646 Davis Nov. 2, 1909 1,623,965 Marshall Apr. 12, 1927' 1,927,499 Nell et a1 Sept. 19, 1933 2,026,666 Benham Jan. 7, 1936 2,638,207 Gutter-man May-12,1953 

